Luis ate 5 slices of pizza. Emily ate 2 slices. If Luis ate $\dfrac{5}{8}$ of the pizza, what fraction of the pizza is remaining?
Explanation: If 5 slices represent $\dfrac{5}{8}$ of the pizza, there must have been a total of 8 slices. $\text{fraction of pizza remaining} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 7 slices, which leaves 1 out of 8 slices remaining. There is $\dfrac{1}{8}$ of the pizza remaining.